US9886010B2ActiveUtilityPatentIndex 39
Method and apparatus for controlling voltage in near direct current area
Est. expiryAug 29, 2034(~8.1 yrs left)· nominal 20-yr term from priority
H02J 3/003H02J 2103/30H02J 3/18Y02E60/60H02J 3/00F03D 7/028F03D 7/045H02J 3/36Y02E40/30G05B 13/048Y02E60/76Y02E10/723H02J 2003/007Y04S40/22Y04S10/54H02J 2003/003Y04S10/50Y02E10/76Y02E60/00Y04S40/20Y02E10/72
39
PatentIndex Score
0
Cited by
6
References
20
Claims
Abstract
The present disclosure relates to a method and an apparatus for controlling a voltage in a near direct current area. The method includes: collecting measured values of parameters as initial values of prediction values of the parameters; inputting the initial values into a preset control model for optimizing a model predictive control; solving the preset control model to obtain a solution sequence of the terminal voltage setting values of the generators participating in the voltage control within a time window; and sending first values in the solution sequence to the generators, such that the voltage control in the near direct current area is realized.
Claims
exact text as granted — not AI-modifiedWhat is claimed is:
1. A method for controlling a voltage in a near direct current area, wherein the method is applied in a control of an automatic voltage control system in a master station of a power system and comprises following steps:
collecting measured values of parameters as initial values of prediction values of the parameters, wherein the prediction values comprise voltage prediction values of pilot buses, a voltage prediction value of a bus in a convertor station, a first active power prediction value which is a sum of active power prediction values of loads in the convertor station, a first reactive power prediction value which is a sum of reactive power prediction values of the loads in the convertor station, an input amount of capacitors and reactors in the convertor station, terminal voltage prediction values of generators participating in a voltage control, active power prediction values of the generators and reactive power prediction values of the generators;
inputting the initial values into a preset control model for optimizing a model predictive control, wherein the preset control model comprises an objective function and constraint conditions, the objective function is a function established according to the voltage prediction values of the pilot buses and the terminal voltage prediction values of the generators, and configured to optimize terminal voltage setting values of generators, the constraint conditions comprise a first constraint condition of the reactive power prediction values of the generators, a second constraint condition of the voltage prediction values of the pilot buses, the voltage prediction value of the bus in the convertor station, the terminal voltage prediction values of the generators, a third constraint condition of the input amount of the capacitors and reactors in the convertor station, a fourth constraint condition of an input amount of filter capacitors under a constant reactive power mode, a fifth constraint condition of a number of actions of the capacitors and reactors and a sixth constraint condition of a system voltage, the reactive power prediction values of the generators and the input amount of the capacitors and reactors in the convertor station;
solving the preset control model to obtain a solution sequence of the terminal voltage setting values of the generators within a time window;
sending first values in the solution sequence to the generators, such that the voltage control in the near direct current area is realized.
2. The method according to claim 1 , wherein the first active power prediction value, the first reactive power prediction value and the active power prediction values of the generators are evaluated according to a generation schedule and a load forecasting result.
3. The method according to claim 1 , further comprising:
establishing the preset control model.
4. The method according to claim 3 , wherein establishing the preset control model comprises:
establishing the objective function according to formula (1):
min
V
G
set
∑
i
=
0
N
-
1
∑
j
=
0
M
-
1
ρ
t
i
,
j
F
1
(
1
)
where V G set represents the terminal voltage setting values of the generators, N represents a number of control cycles covered by the time window, M represents a number of predicted points in a single control cycle, ρ represents an attenuation coefficient, ρ<1, t i,j =(Mi+j)Δt represents a prediction time corresponding to a (j+1) th predicted point in a (i+1) th control cycle, Δt represents a time interval between prediction time corresponding to each two adjacent predicted points, F 1 represents a distance between the voltage prediction values of the pilot buses and voltage reference values of the pilot buses, wherein F 1 is denoted by formula (2):
F 1 ( t i,j )=∥ V Pilot pre ( t i,j )− V Pilot ref ∥ 2 (2)
where F 1 (t i,j ) represents a distance between the voltage prediction values of the pilot buses and voltage reference values of the pilot buses at the prediction time t i,j , V Pilot Pre (t i,j ) represents the voltage prediction values of the pilot buses at the prediction time t i,j , V Pilot ref represents the voltage reference values of the pilot buses;
simplifying the objective function according to formula (3) to obtain a simplified objective function, wherein the formula (3) is expressed as:
min
∑
i
=
0
N
-
1
∑
j
=
0
M
-
1
ρ
t
i
,
j
F
2
(
3
)
where F 2 represents a distance between the terminal voltage prediction values of the generators and terminal voltage setting values of the generators; F 2 is denoted by formula (4):
F 2 ( t i,j )=∥ V G pre ( t i,j )− V G set ( t i,0 )∥ 2 (4)
where F 2 (t i,j ) represents a distance between the terminal voltage prediction values of the generators and terminal voltage setting values of the generators at the predication time t i,j , V G pre (t i,j ) represents the terminal voltage prediction values of the generators at the predication time t i,j , V G set (t i,0 ) represents the terminal voltage setting values of the generators at a prediction time t i,0 , t i,0 =(Mi)Δt represents a prediction time corresponding to a first predicted point in the (i+1) th control cycle;
the simplified objective function is denoted by formula (5):
min
∑
i
=
0
N
-
1
∑
j
=
0
M
-
1
ρ
t
i
,
j
(
F
1
+
wF
2
)
(
5
)
where w represents a weight corresponding to F 2 .
5. The method according to claim 4 , wherein the first constraint condition is denoted by formula (6):
Q
G
ref
(
t
i
,
j
)
=
K
P
[
V
G
pre
(
t
i
,
j
)
-
V
G
set
(
t
i
,
0
)
]
+
K
I
Δ
t
∑
k
=
0
i
×
M
+
j
[
V
G
pre
(
t
i
,
j
-
k
)
-
V
G
set
(
t
i
,
-
k
)
]
+
Q
G
pre
(
t
0
,
0
)
-
K
P
[
V
G
pre
(
t
0
,
0
)
-
V
G
set
(
t
0
,
0
)
]
Q
G
pre
(
t
i
,
j
)
=
Q
G
ref
(
t
i
,
j
-
1
)
+
[
Q
G
pre
(
t
i
,
j
-
1
)
-
Q
G
ref
(
t
i
,
j
-
1
)
]
e
-
(
t
i
,
j
-
t
i
,
j
-
1
)
/
T
d
(
6
)
where Q G ref (t i,j ) represents reactive power reference values of the generators at the prediction time t i,j , V G pre (t i,j−k ) represents the terminal voltage prediction values of the generators at a prediction time t i,j−k , t i,j−k =(Mi+j−k)Δt, V G set (t i,−k ) represents the terminal voltage setting values of the generators at a prediction time t i,−k , t i,−k =(Mi−k)Δt, Q G pre (t 0,0 ) represents reactive power prediction values of the generators at a current time t 0,0 , V G pre (t 0,0 ) represents the terminal voltage prediction values of the generators at the current time t 0,0 , V G set (t 0,0 ) represents the terminal voltage setting values of the generators at the current time t 0,0 , K I represents coefficients in a proportion calculation, K P represents coefficients in an integral calculation, Q G pre (t i,j ) is a component of Q G pre (t i,j ) and represents a reactive power prediction value of a generator at the prediction time t i,j , Q G pre (t i,j ) represents the reactive power prediction values of the generators at the prediction time t i,j , Q G ref (t i,j−1 ) is a component of Q G ref (t i,j−1 ) and represents a reactive power reference value of the generator at a prediction time t i,j−1 , Q G ref (t i,j−1 ) represents the reactive power reference values of the generators at the prediction time t i,j−1 , Q G pre (t i,j−1 ) is a component of Q G pre (t i,j−1 ) and represents a reactive power prediction value of the generator at the prediction time t i,j−1 , Q G pre (t i,j−1 ) represents the reactive power prediction values of the generators at the prediction time t i,j−1 , t i,j−1 =(Mi+j−1)Δt, T d represents an action delay of a generator excitation regulator.
6. The method according to claim 5 , wherein the second constraint condition is denoted by formula (7)
V
pre
(
t
i
,
j
)
-
V
pre
(
t
0
,
0
)
=
S
[
P
G
pre
(
t
i
,
j
)
-
P
G
pre
(
t
0
,
0
)
Q
G
pre
(
t
i
,
j
)
-
Q
G
pre
(
t
0
,
0
)
-
P
St
pre
(
t
i
,
j
)
+
P
St
pre
(
t
0
,
0
)
-
Q
St
pre
(
t
i
,
j
)
+
Q
St
pre
(
t
0
,
0
)
+
Q
St
C
[
N
St
pre
(
t
i
,
j
)
-
N
St
pre
(
t
0
,
0
)
]
]
(
7
)
where V pre (t i,j ) represents a vector composing of the voltage prediction values of the pilot buses, the voltage prediction value of the bus in the convertor station and the terminal voltage prediction values of the generators at the prediction time t i,j , V pre (t 0,0 ) represents the vector composing of the voltage prediction values of the pilot buses, the voltage prediction value of the bus in the convertor station and the terminal voltage prediction values of the generators at the current time t 0,0 , S represents a sensitivity matrix and is determined by the automatic voltage control system, P G pre (t i,j ) represents the active power prediction values of the generators at the prediction time t i,j , P G pre (t 0,0 ) represents the active power prediction values of the generators at the current time t 0,0 , Q G pre (t 0,0 ) represents the reactive power prediction values of the generators at the current time t 0,0 , P St pre (t i,j ) represents the first active power prediction value at the prediction time t i,j , P St pre (t 0,0 ) represents the first active power prediction value at the current time t 0,0 , Q St pre (t i,j ) represents the first reactive power prediction value at the prediction time t i,j , Q St pre (t 0,0 ) represents the first reactive power prediction value at the current time t 0,0 , Q St C represents a capacitance of a single capacitor, N St pre (t i,j ) represents the input amount of the capacitors and reactors in the convertor station at the prediction time t i,j and N St pre (t 0,0 ) represents the input amount of the capacitors and reactors in the convertor station at the current time t 0,0 .
7. The method according to claim 6 , wherein the third constraint condition is denoted by formula (8):
V
^
pre
(
t
i
,
j
)
-
V
pre
(
t
0
,
0
)
=
S
[
P
G
pre
(
t
i
,
j
)
-
P
G
pre
(
t
0
,
0
)
Q
G
pre
(
t
i
,
j
)
-
Q
G
pre
(
t
0
,
0
)
-
P
St
pre
(
t
i
,
j
)
+
P
St
pre
(
t
0
,
0
)
-
Q
St
pre
(
t
i
,
j
)
+
Q
St
pre
(
t
0
,
0
)
+
Q
St
C
[
N
St
pre
(
t
i
,
j
-
1
)
-
N
St
pre
(
t
0
,
0
)
]
]
N
St
pre
(
t
i
,
j
)
=
{
N
St
pre
(
t
i
,
j
-
1
)
-
1
,
V
^
St
pre
>
V
St
max
N
St
pre
(
t
i
,
j
-
1
)
-
1
,
V
^
St
pre
<
V
St
min
N
St
pre
(
t
i
,
j
-
1
)
,
else
(
8
)
where {circumflex over (V)} pre (t i,j ) represents a vector composing of the voltage prediction values of the pilot buses, the voltage prediction value of the bus in the convertor station and the terminal voltage prediction values of the generators at the prediction time t i,j before an action is performed by the capacitors and reactors, S represents a sensitivity matrix and is determined by the automatic voltage control system, N St pre (t i,j−1 ) represents the input amount of the capacitors and reactors in the convertor station at the prediction time t i,j−1 , V St max represents an upper limit of the voltage prediction value of the bus in the convertor station, V St min represents a lower limit of the voltage prediction value of the bus in the convertor station, {circumflex over (V)} St pre is a component in {circumflex over (V)} pre and represents the voltage prediction value of the bus in the convertor station before an action is performed by the capacitors and reactors.
8. The method according to claim 7 , wherein the fourth constraint condition is denoted by formula (9):
Q
^
St
,
out
pre
=
-
Q
St
pre
(
t
i
,
j
)
+
Q
St
C
N
St
pre
(
t
i
,
j
-
1
)
N
St
pre
(
t
i
,
j
)
=
{
N
St
pre
(
t
i
,
j
-
1
)
-
1
,
Q
^
St
,
out
pre
>
Q
St
,
out
max
N
St
pre
(
t
i
,
j
-
1
)
+
1
,
Q
^
St
,
out
pre
<
Q
St
,
out
min
N
St
pre
(
t
i
,
j
-
1
)
,
else
(
9
)
where {circumflex over (Q)} St,out pre represents a total reactive power injected into the power system by the converter station before an action of the filter capacitors, Q St,out max represents an upper limit of the total reactive power injected into the power system by the converter station before an action of the filter capacitors, Q St,out min represents a lower limit of the total reactive power injected into the power system by the converter station before an action of the filter capacitors.
9. The method according to claim 8 , wherein the fifth constraint condition is denoted by formula (10):
-
O
St
pre
(
t
i
,
j
)
≤
N
St
pre
(
t
i
,
j
)
-
N
St
pre
(
t
i
,
j
-
1
)
≤
O
St
pre
(
t
i
,
j
)
∑
i
=
0
N
-
1
∑
j
=
0
M
-
1
O
St
pre
(
t
i
,
j
)
≤
O
St
max
(
10
)
where O St pre (t i,j ) is an indicator indicating whether the capacitors and reactors are static at the prediction time t i,j , O St max or represents an upper limit of the number of actions of the capacitors and reactors.
10. The method according to claim 9 , wherein the sixth constraint condition is denoted by formula (11)
{
V
min
≤
V
pre
(
t
i
,
j
)
≤
V
max
Q
G
min
≤
Q
G
pre
(
t
i
,
j
)
≤
Q
G
max
N
St
min
≤
N
St
pre
(
t
i
,
j
)
≤
N
St
max
(
11
)
where V max represents upper limits of the vector composing of the voltage prediction values of the pilot buses, the voltage prediction value of the bus in the convertor station and the terminal voltage prediction values of the generators, V min represents lower limits of the vector composing of the voltage prediction values of the pilot buses, the voltage prediction value of the bus in the convertor station and the terminal voltage prediction values of the generators, Q G max represents upper limits of the reactive power prediction values of the generators, Q G min represents lower limits of the reactive power prediction values of the generators, N St max represents an upper limit of the input amount of the capacitors and reactors and N St min represents a lower limit of the input amount of the capacitors and reactors.
11. An apparatus for controlling a voltage in a near direct current area, wherein the apparatus is applied in a control of an automatic voltage control system in a master station of a power system and comprises:
a processor; and
a memory for storing instructions executable by the processor;
wherein the processor is configured to
collect measured values of parameters as initial values of prediction values of the parameters, wherein the prediction values comprise voltage prediction values of pilot buses, a voltage prediction value of a bus in a convertor station, a first active power prediction value which is a sum of active power prediction values of loads in the convertor station, a first reactive power prediction value which is a sum of reactive power prediction values of the loads in the convertor station, an input amount of capacitors and reactors in the convertor station, terminal voltage prediction values of generators participating in a voltage control, active power prediction values of the generators and reactive power prediction values of the generators;
input the initial values into a preset control model for optimizing a model predictive control, wherein the preset control model comprises an objective function and constraint conditions, the objective function is a function established according to the voltage prediction values of the pilot buses and the terminal voltage prediction values of the generators, and configured to optimize terminal voltage setting values of the generators, the constraint conditions comprise a first constraint condition of the reactive power prediction values of the generators, a second constraint condition of the voltage prediction values of the pilot buses, the voltage prediction value of the bus in the convertor station, the terminal voltage prediction values of the generators, a third constraint condition of the input amount of the capacitors and reactors in the convertor station, a fourth constraint condition of an input amount of filter capacitors under a constant reactive power mode, a fifth constraint condition of a number of actions of the capacitors and reactors and a sixth constraint condition of a system voltage, the reactive power prediction values of the generators and the input amount of the capacitors and reactors in the convertor station;
solve the preset control model to obtain a solution sequence of the terminal voltage setting values of the generators within a time window;
send first values in the solution sequence to the generators, such that the voltage control in the near direct current area is realized.
12. The apparatus according to claim 11 , the processor is further configured to:
establish the preset control model.
13. The apparatus according to claim 12 , wherein the processor is further configured to:
establish the objective function according to formula (1):
min
V
G
set
∑
i
=
0
N
-
1
∑
j
=
0
M
-
1
ρ
t
i
,
j
F
1
(
1
)
where V G set represents the terminal voltage setting values of the generators, N represents a number of control cycles covered by the time window, M represents a number of predicted points in a single control cycle, ρ represents an attenuation coefficient, ρ<1, t i,j =(Mi+j)Δt represents a prediction time corresponding to a (j+1) th predicted point in a (i+1) th control cycle, Δt represents a time interval between prediction time corresponding to each two adjacent predicted points, F 1 represents a distance between the voltage prediction values of the pilot buses and voltage reference values of the pilot buses, wherein F 1 is denoted by formula (2):
F 1 ( t i,j )=∥ V Pilot pre ( t i,j )− V Pilot ref ∥ 2 (2)
where F 1 (t i,j ) represents a distance between the voltage prediction values of the pilot buses and voltage reference values of the pilot buses at the prediction time t i,j , V Pilot Pre (t i,j ) represents the voltage prediction values of the pilot buses at the prediction time t i,j , V Pilot ref represents the voltage reference values of the pilot buses;
simplify the objective function according to formula (3) to obtain a simplified objective function, wherein the formula (3) is expressed as:
min
∑
i
=
0
N
-
1
∑
j
=
0
M
-
1
ρ
t
i
,
j
F
2
(
3
)
where F 2 represents a distance between the terminal voltage prediction values of the generators and terminal voltage setting values of the generators; F 2 is denoted by formula (4):
F 2 ( t i,j )=∥ V G pre ( t i,j )− V G set ( t i,0 )∥ 2 (4)
where F 2 (t i,j ) represents a distance between the terminal voltage prediction values of the generators and terminal voltage setting values of the generators at the predication time t i,j , V G pre (t i,j ) represents the terminal voltage prediction values of the generators at the predication time t i,j , V G set (t i,0 ) represents the terminal voltage setting values of the generators at a prediction time t i,0 t i,0 =(Mi)Δt represents a prediction time corresponding to a first predicted point in the (i+1) th control cycle;
the simplified objective function is denoted by formula (5):
min
∑
i
=
0
N
-
1
∑
j
=
0
M
-
1
ρ
t
i
,
j
(
F
1
+
w
F
2
)
(
5
)
where w represents a weight corresponding to F 2 .
14. The apparatus according to claim 13 , wherein the first constraint condition is denoted by formula (6):
Q
G
ref
(
t
i
,
j
)
=
K
P
[
V
G
pre
(
t
i
,
j
)
-
V
G
set
(
t
i
,
0
)
]
+
K
I
Δ
t
∑
k
=
0
i
×
M
+
j
[
V
G
pre
(
t
i
,
j
-
k
)
-
V
G
set
(
t
i
,
-
k
)
]
+
Q
G
pre
(
t
0
,
0
)
-
K
P
[
V
G
pre
(
t
0
,
0
)
-
V
G
set
(
t
0
,
0
)
]
Q
G
pre
(
t
i
,
j
)
=
Q
G
ref
(
t
i
,
j
-
1
)
+
[
Q
G
pre
(
t
i
,
j
-
1
)
-
Q
G
ref
(
t
i
,
j
-
1
)
]
e
-
(
t
i
,
j
-
t
i
,
j
-
1
)
/
T
d
(
6
)
where Q G ref (t i,j ) represents reactive power reference values of the generators at the prediction time t i,j , V G pre (t i,j−k ) represents the terminal voltage prediction values of the generators at a prediction time t i,j−k , t i,j−k =(Mi+j−k)Δt, V G set (t i,−k ) represents the terminal voltage setting values of the generators at a prediction time t i,−k , t i,−k =(Mi−k)Δt, Q G pre (t 0,0 ) represents reactive power prediction values of the generators at a current time t 0,0 , V G pre (t 0,0 ) represents the terminal voltage prediction values of the generators at the current time t 0,0 , V G set (t 0,0 ) represents the terminal voltage setting values of the generators at the current time t 0,0 , K I represents coefficients in a proportion calculation, K P represents coefficients in an integral calculation, Q G pre (t i,j ) is a component of Q G pre (t i,j ) and represents a reactive power prediction value of a generator at the prediction time t i,j , Q G ref (t i,j−1 ) represents the reactive power prediction values of the generators at the prediction time t i,j , Q G ref (t i,j−1 ) is a component of Q G ref (t i,j−1 ) and represents a reactive power reference value of the generator at a prediction time t i,j−1 , Q G ref (t i,j−1 ) represents the reactive power reference values of the generators at the prediction time t i,j−1 , Q G pre (t i,j−1 ) is a component of Q G pre (t i,j−1 ) and represents a reactive power prediction value of the generator at the prediction time t i,j−1 , Q G pre (t i,j−1 ) represents the reactive power prediction values of the generators at the prediction time t i,j−1 , t i,j−1 =(Mi+j−1)Δt, T d represents an action delay of a generator excitation regulator.
15. The apparatus according to claim 14 wherein the second constraint condition is denoted by formula (7):
V
pre
(
t
i
,
j
)
-
V
pre
(
t
0
,
0
)
=
S
[
P
G
pre
(
t
i
,
j
)
-
P
G
pre
(
t
0
,
0
)
Q
G
pre
(
t
i
,
j
)
-
Q
G
pre
(
t
0
,
0
)
-
P
St
pre
(
t
i
,
j
)
+
P
St
pre
(
t
0
,
0
)
-
Q
St
pre
(
t
i
,
j
)
+
Q
St
pre
(
t
0
,
0
)
+
Q
St
C
[
N
St
pre
(
t
i
,
j
)
-
N
St
pre
(
t
0
,
0
)
]
]
(
7
)
where V pre (t i,j ) represents a vector composing of the voltage prediction values of the pilot buses, the voltage prediction value of the bus in the convertor station and the terminal voltage prediction values of the generators at the prediction time t i,j , V pre (t 0,0 ) represents the vector composing of the voltage prediction values of the pilot buses, the voltage prediction value of the bus in the convertor station and the terminal voltage prediction values of the generators at the current time t 0,0 , S represents a sensitivity matrix and is determined by the automatic voltage control system, P G pre (t i,j ) represents the active power prediction values of the generators at the prediction time t i,j , P G pre (t 0,0 ) represents the active power prediction values of the generators at the current time t 0,0 , Q G pre (t 0,0 ) represents the reactive power prediction values of the generators at the current time t 0,0 , P St pre (t i,j ) represents the first active power prediction value at the prediction time t i,j , P St pre (t 0,0 ) represents the first active power prediction value at the current time t 0,0 , Q St pre (t i,j ) represents the first reactive power prediction value at the prediction time t i,j , Q St pre (t 0,0 ) represents the first reactive power prediction value at the current time t 0,0 , Q St C represents a capacitance of a single capacitor, N St pre (t i,j ) represents the input amount of the capacitors and reactors in the convertor station at the prediction time t i,j and N St pre (t 0,0 ) represents the input amount of the capacitors and reactors in the convertor station at the current time t 0,0 .
16. The apparatus according to claim 15 , wherein the third constraint condition is denoted by formula (8):
V
^
pre
(
t
i
,
j
)
-
V
pre
(
t
0
,
0
)
=
S
[
P
G
pre
(
t
i
,
j
)
-
P
G
pre
(
t
0
,
0
)
Q
G
pre
(
t
i
,
j
)
-
Q
G
pre
(
t
0
,
0
)
-
P
St
pre
(
t
i
,
j
)
+
P
St
pre
(
t
0
,
0
)
-
Q
St
pre
(
t
i
,
j
)
+
Q
St
pre
(
t
0
,
0
)
+
Q
St
C
[
N
St
pre
(
t
i
,
j
-
1
)
-
N
St
pre
(
t
0
,
0
)
]
]
N
St
pre
(
t
i
,
j
)
=
{
N
St
pre
(
t
i
,
j
-
1
)
-
1
,
V
^
St
pre
>
V
St
max
N
St
pre
(
t
i
,
j
-
1
)
-
1
,
V
^
St
pre
<
V
St
min
N
St
pre
(
t
i
,
j
-
1
)
,
else
(
8
)
where {circumflex over (V)} pre (t i,j ) represents a vector composing of the voltage prediction values of the pilot buses, the voltage prediction value of the bus in the convertor station and the terminal voltage prediction values of the generators at the prediction time t i,j before an action is performed by the capacitors and reactors, S represents a sensitivity matrix and is determined by the automatic voltage control system, N St pre (t i,j−1 ) represents the input amount of the capacitors and reactors in the convertor station at the prediction time t i,j−1 , V St max represents an upper limit of the voltage prediction value of the bus in the convertor station, V St min represents a lower limit of the voltage prediction value of the bus in the convertor station, {circumflex over (V)} St pre is a component in {circumflex over (V)} pre and represents the voltage prediction value of the bus in the convertor station before an action is performed by the capacitors and reactors.
17. The apparatus according to claim 16 , wherein the fourth constraint condition is denoted by formula (9):
Q
^
St
,
out
pre
=
-
Q
St
pre
(
t
i
,
j
)
+
Q
St
C
N
St
pre
(
t
i
,
j
-
1
)
N
St
pre
(
t
i
,
j
)
=
{
N
St
pre
(
t
i
,
j
-
1
)
-
1
,
Q
^
St
,
out
pre
>
Q
St
,
out
max
N
St
pre
(
t
i
,
j
-
1
)
+
1
,
Q
^
St
,
out
pre
<
Q
St
,
out
min
N
St
pre
(
t
i
,
j
-
1
)
,
else
(
9
)
where {circumflex over (Q)} St,out pre represents a total reactive power injected into the power system by the converter station before an action of the filter capacitors, Q St,out max represents an upper limit of the total reactive power injected into the power system by the converter station before an action of the filter capacitors, Q St,out min represents a lower limit of the total reactive power injected into the power system by the converter station before an action of the filter capacitors.
18. The apparatus according to claim 17 , wherein the fifth constraint condition is denoted by formula (10):
-
O
St
pre
(
t
i
,
j
)
≤
N
St
pre
(
t
i
,
j
)
-
N
St
pre
(
t
i
,
j
-
1
)
≤
O
St
pre
(
t
i
,
j
)
∑
i
=
0
N
-
1
∑
j
=
0
M
-
1
O
St
pre
(
t
i
,
j
)
≤
O
St
max
(
10
)
where O St pre (t i,j ) is an indicator indicating whether the capacitors and reactors are static at the prediction time t i,j , O St max or represents an upper limit of the number of actions of the capacitors and reactors.
19. The apparatus according to claim 18 , wherein the sixth constraint condition is denoted by formula (11):
{
V
min
≤
V
pre
(
t
i
,
j
)
≤
V
max
Q
G
min
≤
Q
G
pre
(
t
i
,
j
)
≤
Q
G
max
N
St
min
≤
N
St
pre
(
t
i
,
j
)
≤
N
St
max
(
11
)
where V max represents upper limits of the vector composing of the voltage prediction values of the pilot buses, the voltage prediction value of the bus in the convertor station and the terminal voltage prediction values of the generators, V min represents lower limits of the vector composing of the voltage prediction values of the pilot buses, the voltage prediction value of the bus in the convertor station and the terminal voltage prediction values of the generators, Q G max represents upper limits of the reactive power prediction values of the generators, Q G min represents lower limits of the reactive power prediction values of the generators, N St max represents an upper limit of the input amount of the capacitors and reactors and N St min represents a lower limit of the input amount of the capacitors and reactors.
20. A non-transitory computer-readable storage medium having stored therein instructions that, when executed by a processor of a computer, causes the computer to perform a method for controlling a voltage in a near direct current area, the method comprising:
collecting measured values of parameters as initial values of prediction values of the parameters, wherein the prediction values comprise voltage prediction values of pilot buses, a voltage prediction value of a bus in a convertor station, a first active power prediction value which is a sum of active power prediction values of loads in the convertor station, a first reactive power prediction value which is a sum of reactive power prediction values of the loads in the convertor station, an input amount of capacitors and reactors in the convertor station, terminal voltage prediction values of generators participating in a voltage control active power prediction values of the generators and reactive power prediction values of the generators;
inputting the initial values into a preset control model for optimizing a model predictive control, wherein the preset control model comprises an objective function and constraint conditions, the objective function is a function established according to the voltage prediction values of the pilot buses and the terminal voltage prediction values of the generators, and configured to optimize terminal voltage setting values of generators, the constraint conditions comprise a first constraint condition of the reactive power prediction values of the generators, a second constraint condition of the voltage prediction values of the pilot buses, the voltage prediction value of the bus in the convertor station, the terminal voltage prediction values of the generators, a third constraint condition of the input amount of the capacitors and reactors in the convertor station, a fourth constraint condition of an input amount of filter capacitors under a constant reactive power mode, a fifth constraint condition of a number of actions of the capacitors and reactors and a sixth constraint condition of a system voltage, the reactive power prediction values of the generators and the input amount of the capacitors and reactors in the convertor station;
solving the preset control model to obtain a solution sequence of the terminal voltage setting values of the generators within a time window;
sending first values in the solution sequence to the generators, such that the voltage control in the near direct current area is realized.Cited by (0)
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